The present invention relates to a device for mooring a boat or other vessel, e.g. a mooring hook, pulley, shackle, winch or fairlead, or for mooring to a towing vessel.
To ensure safe and efficient mooring of large vessels the tensions in mooring lines must be monitored to reduce the risk of the vessel accidentally breaking away from its berth, e.g. a jetty, anchor or buoy, or a towing vessel.
Existing methods of computing the mooring line tensions are to attach linear strain gauges to the side plates of the mooring hook or pulley, so that the axis of the gauges is in alignment with the expected direction of the maximum principal stress. Alternatively, a gauge rosette may be attached to the side plates of the hook or pulley, which will measure the maximum principal stress and indicate the direction through which the stress is acting. Neither of these two methods is wholly satisfactory as the gauge installations are susceptible to physical damage and unknown stresses present in the side plates may produce misleading information.
It is a purpose of the present invention to provide an improved means of load sensing which may be used to provide satisfactory efficiency in the operation of mooring installations.
It has now been found that a mooring device comprising a pin in a pivotal joint can best be monitored for stress by providing a strain sensor on the pin itself.